Effect of wall orientation of the sand concrete lightened by wood shavings on the time lag and the decrement factor

Abstract

The development of new lightweight concrete based on the valorization of local materials and waste in construction is an environmental and sustainable approach. In this context, the studied composite is a sand concrete (dune and alluvial) lightened by wood shavings to improve its thermophysical properties. The objective is to investigate the orientation effect of an outside wall made with this material in an arid environment on the thermophysical properties of the wall, namely the time lag (Φ) and the decrement factor (f). The experimental study has been dedicated, first of all, to determine the optimal composition of sand concrete lightened by wood shavings, which the content is 60 kg/m3. This composition is a compromise between studied compactness and workability. Then, to study the thermal properties of the sand concrete without wood shavings (SC-W-WS) and sand concrete lightened by wood shavings (SC-WS). Finally, a numerical simulation using the EnergyPlus software was made to study the wall orientation effect designed in the Laghouat city (south of Algeria). The results obtained show that the substitution of sand by wood shavings has improved thermal properties of the wood sand concrete namely: the thermal conductivity, the specific heat and the thermal diffusivity. The simulation results are very interesting, because all orientations are right for the sand concrete lightened by wood shavings (SC-WS). Nevertheless, the north and the west orientations are wrong in the case of the sand concrete (SC-W-WS). However, the east orientation has the longest time lag, which is consistent with the literature. The advantage of these results is in favour of concrete having improved thermophysical properties.